SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '254b4f6e982379ee9e1a3cd0af6964a883c5636a51f06202b72c24122f10398e' 
  AND token = '782GSFiLY703fTm/m+cek9iPF4b0Hn5J5U9YcXRAoSc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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