SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1ca46cbcb23b68975cf500d046b1ca9cc54ce7883e4033463f8a199e08138ce3' 
  AND token = 'wD14schrv+7AcCXfSbBLeBWKxSBZmUeLdAgat2AaIYQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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