SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f99db62fddd24cef13943786384f01f81990a99c1efcb23c5a5077dc04209359' 
  AND token = 'VqLczKl0jtsPANB0uPz0+WhZtUpA4LL45QQsuVToAz4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00045

JSON explain

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