SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '27b2f4e0cd0fed59e2db5ab7e77f6aade341469b387230494c34e8af11436699' 
  AND token = 'Dp/GOb182Jey7QsQsRBDbXbiCP9lkpgMcHJNalxX5C8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00014

JSON explain

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