SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'faeaa922fe9219755689d3ac84195ce64433fdc9a84895f27112cbecbc2d3275' 
  AND token = 'U5I9wLH/PMTT1dByxU2m3vPEnlmXGZMx9bhj/XCOF6g=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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