SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cc335fa30b4420ea111945d2df28c1782e442c7699dd48e1a14a24711f3afa2a' 
  AND token = 'OO4dYvPTWHL1/xSO7y7kPafrPLG8w09hn0ygfLNwamY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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