SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '354001dcaac6772daa026d43cadce1ed2b747881870790eebaa62d967164e132' 
  AND token = 'IJRWp761TYBmpq4xt1wfqvFnEpLbfbbrAFzupQT4tns=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00011

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}