SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5c037870656fa8c1b4a0e31151794b02cdf3ef3bbe64f64d2846c68298ed62a6' 
  AND token = 'kQ+WKB3L9pruV1REUgun0dsiyZCDGTPKwOZYRQAWks4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00011

JSON explain

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