SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f70188b9a1d471e10729f0c80fe8b5809c20b1ae4f6642f4c3b679d567777d41' 
  AND token = 'uCNHxlmUtuOqzghaNiyC4TZxYMGAyM+g4tX7J1mGsjI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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