SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '50a0e2d1af127de3c4c319306c363a0763f063950febe488e4342e0caeeca256' 
  AND token = '3VoqG6/4qqfAqQJDvyDWSlOc6vsw5yaW23k6slVL8fY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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