SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7b72586ffa46bd31e0a01cdde482b5362ba6b4aa1699c478e1e79011d1146629' 
  AND token = '+wO7jzRNw+4AH+yvFT1IG/BQYhEHv1fdBnXKHQuJEKA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00045

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}