SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ee19f955bddbb14519a434b950d1f4a9030860399e6e6aea9c170432483bb43e' 
  AND token = 'iAlOn0lr1rDUKEggJQ4OFFK3f1JtqCiLpH8WMMKZziM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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