SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1146e6ed551794d3fc32b982e8a313f48d98240ccd195e46c2d79724af369a2f' 
  AND token = 'lQ+96m7zFot1SYeNreimsODxTCvjPdb+faOsGuhdN6I=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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