SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3ebfe0faf7f47aacf022e3ad5deffa641322343b609e70b7405d71a565b26554' 
  AND token = 'M/NynP2/J3SkssYhktqfyIvbyFrWikhSVkeTtk4R/jc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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