SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '113b889b735ce5c87d4ce67de0d324de9e196de5dc0e23c3a22285d6be17ecdb' 
  AND token = 'Emh4rKKLGxCMy1hJqa4hJGj+v2Wb01LHfjxf0yn+UL8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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