SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9cd8764a7627b734db9d0ec6468eaa206cbf0eb394799223606834a371ee02b3' 
  AND token = 'xGUzff4vbkMSUWJPALCDUpLlsJ4PpaonzUEjWvgeS0A=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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