SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '74320b164c998c58dc58d3b02c99cb5463505498327043e08dadd2b0abbe3748' 
  AND token = 'hNt6fv2Qo/55+E46lNKVB+sLPNVngVGuC77DopFOjhs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00013

JSON explain

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