SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '6fcabc0fe42a3f84d3fe30af3815dd1d0c36bf472fee43161f7e645e2c20256f' 
  AND token = 'j4H61BYXgSGF2AhtWuGjZP3shFN6ATs9SkKJPpQA+FI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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