SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e2674db274c26b6f0e9f1ed0d638181c8dc70852d475e271e9380ff5c1fdacbc' 
  AND token = 'tSxyBWz+/uL98k2gtRtBrP6YNiycuVF0d18F+TDNAQY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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