SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cedf4345845e9875a5332891a80dda225b5b0d4c8f0dd7ce1c8e5e09494a42b3' 
  AND token = '53vpNJ5khR2PIAAjgqIBrlz/N8apib9Qtoj3biUAgTA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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