SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '00d637a813a0d5848f19515d483912018aab82633973b7f7c87276c21b22ec2a' 
  AND token = 'T2z41u5cIwsjCL9nPhwENWIRWreEDvJOY31Ge5PttAA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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