SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e6bac09644199bb6c829dea2b5f6cace8a7091cb758b114f6ece8c7a623ee6c9' 
  AND token = 'rYYPu1q3t5pfU03uTFYeC/86GI2LlNDoHGGxvLvVYZI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00073

JSON explain

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