SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'f2481f28cc991701248d16458ab812499ff050c8a3cf58a5c18045419d8a2991' 
  AND token = 'ujxVQdindKcb+uRevjRm/CC9jTrQfkKeYQ0Ufe/rNtU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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