SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2e82a58ed137e515f6113ff3eb3d713fe43c465b1ddaf63ec783782cc75c0b7d' 
  AND token = 'g4Qx+RIt6psT2hsUBBCv8zn3Yoa5pXLUXKMRIVL6NHQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00102

JSON explain

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