SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '75e228b5ab27bfcc8b0c5a017955029b0fa02c575d7def1995571a620095f82e' 
  AND token = 'BOXBZYvWy+dZKzxGFG1VZJP6fOGe3RPcDDFuR+yfHH4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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