SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b7195698ff7d37eb4ed7692a7c543856f06d0ad644de224e2abc713ab3413bda' 
  AND token = 'okLtLB+X6hzOUle4NaLlrjqinkGPZbFdyUlIMBAeUpU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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